Domain characterization for Schrödinger operators with sub-quadratic singularity

We characterize the domain of the Schrödinger operators $S=-\mathrm{\Delta }+c\mathrm{\mid }x{\mathrm{\mid }}^{-\alpha }$ in $L^p({\mathbb{R}}^N)$, with $0<\alpha <2$ and $c\in \mathbb{R}$. When $\alpha p<N$, the domain characterization is essentially known and can be proved using different tools, for instance kernel estimates and potentials in the Kato class or in the reverse Hölder class. However,the other cases seem not to be known, so far.In this paper, we give the explicit description of the domain of $S$ for all range of parameters $p,\alpha$ and $c$.